Sure, what happens in the classroom matters. But peer-reviewed research shows over and over again that between 2/3 and 4/5 of student achievement is based on non-school factors. Schools only contribute about 20% to 33% to students’ overall learning outcomes.

In addition, teachers are only part of the school equation. They’re the most important part, but non-teacher factors such as administrators, curriculum, other students in the school, available learning resources, and so on also impact student achievement. So teachers are responsible for about half (or so) of the school impact, but the rest lies outside their domain.

When you add all of this up, good teachers clearly are absolutely critical to student academic success. But their overall impact on student learning falls around 10% to 17%. Other in-school and out-of-school factors account for the rest. What this means is that – the occasional tale of heroic, exceptional teachers and schools aside – we should be making state and national policy based on what the research shows generally occurs, not exceptions, anecdotes, personal intuition, or unsubstantiated policy/political claims. And we definitely should not be holding teachers 100% accountable for outcomes for which they’re only 1/6 to 1/10 influential.

We need a much broader (and smarter) conversation about what it means to educate our nation’s children.